English
If a | b·c and gcd(a,b) = 1, then a | c.
Русский
Если a делит b·c и gcd(a,b) = 1, тогда a делит c.
LaTeX
$$$$a \\mid bc \\wedge \\gcd(a,b) = 1 \\Rightarrow a \\mid c.$$$$
Lean4
/-- Euclid's lemma: if `a ∣ b * c` and `gcd a b = 1` then `a ∣ c`.
Compare with `IsCoprime.dvd_of_dvd_mul_right` and
`UniqueFactorizationMonoid.dvd_of_dvd_mul_right_of_no_prime_factors` -/
theorem dvd_of_dvd_mul_right_of_gcd_one {a b c : ℤ} (habc : a ∣ b * c) (hab : gcd a b = 1) : a ∣ c :=
by
rw [mul_comm] at habc
exact dvd_of_dvd_mul_left_of_gcd_one habc hab